This application claims the priority of German application 196 23 936.2-12 filed on Jun. 15, 1996, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a bearing of an axle transmission case of the type having a linking at both ends of the transmission cases to respective vehicle support frame members and having an elastic effect in at least one direction. Preferred embodiments relate to a bearing for an axle transmission case for a rear axle transmission.
Bearing arrangements of this general type are known, for example, from German Patent Document DE-OS 15 55 176 and British Patent Document GB 2 204 839A.
Based on the prior systems, the invention concerns the problem of making the bearing arrangement of the axle transmission softer, that is, more flexible, in the driving direction than in the other directions.
The invention provides a solution by providing a bearing of the above-mentioned type wherein the bearing takes place on one of the two ends of the transmission case exclusively by way of at least one lever which can be swivelled in a plane parallel to the vertical and longitudinal axis of the vehicle and which is linked in the direction of the vertical vehicle axis at mutually spaced linking points to the transmission case and to the member frame, at least the bearing of the lever with respect to the member frame taking place by way of at least one elastic bearing.
The invention is based on the idea of transmitting at least a portion of the forces occurring at the transmission case in the longitudinal direction of the vehicle by way of a lever which is swivellably disposed, on the one hand, in the member frame and, on the other hand, on the axle transmission case and in the process providing the linking points in the direction of the vertical axis of the vehicle in a mutually spaced manner. As a result, in the case of relatively slight deformations of the elastic bearing material within the bearings of the member frame by way of the lever arm effect of the lever, increased deflections can be achieved in the longitudinal direction of the vehicle on the other end of the lever swivellably connected with the transmission case. In the other directions, in which the bearings within the member frame are not loaded by way of a lever arm originating from the lever, they behave according to the elasticity of their bearing materials; that is, they behave more stiffly in these directions because they are not stressed there by way of a lever arm. The bearing which connects the lever with the transmission case may be a purely inelastic pivot bearing according to certain contemplated embodiments. In this case, the elasticity of the bearing arrangement originates only from the linking of the lever to the concerned cross member. If the lever is connected with the transmission case by way of several bearings, all of these bearings can be inelastic pivot bearings in the above-mentioned sense.
According to certain preferred embodiments, the lever can have a U-shaped construction and can reach around the transmission case by means of its U-legs.
According to certain preferred embodiments, the member frame can either be elastically or fixedly connected with the vehicle body. In the case of a fixed connection, it may be an integrated component of the vehicle body and therefore represent a constructively simple solution which is only slightly less comfortable than an elastic linking.
In particularly expedient embodiments, a part of the member frame, specifically the cross member situated in front of the axle transmission in the driving direction, as a whole, is used as the lever according to the invention in that the cross member is connected on its longitudinal ends by way of elastic bearings with the side members of the member frame.
The elastic linking of the member frame to the vehicle body, on the one hand, and an elastic linking according to the invention of the forward cross member to the side members to which the vehicle wheels are linked which are assigned to the transmission case, on the other hand, in the case of forces exercised by the road onto the wheels, particularly lateral forces during cornering, permits an elastic lateral bending of the side members in the area of the forward cross member. As a result, the wheels coupled to the concerned side members are adjusted during cornering in the direction of an understeering.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.